California's AB 2533 Expands Permitting Amnesty to Unpermitted ADUs and JADUs

Introduction

As of January 1, 2025, Assembly Bill 2533 is now law, expanding the pathway for California property owners seeking to legalize unpermitted accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs). While AB 2533 does not introduce entirely new regulations under the state’s ADU law, it extends existing legalization provisions to cover ADUs and JADUs constructed before January 1, 2020.

This legislative update provides much-needed clarity and support for property owners looking to bring their unpermitted units into compliance. The bill’s proponents highlight the critical role these units play in addressing California’s housing crisis by increasing the available housing supply and generating rental income for homeowners. However, they also acknowledge the inherent challenges posed by unpermitted structures, particularly regarding safety, habitability, and compliance with local zoning and building codes.

With AB 2533 now in effect, property owners with unpermitted ADUs or JADUs should take advantage of this opportunity to legalize their units and avoid potential enforcement actions. Ensuring compliance not only enhances property value but also provides long-term security for both owners and tenants.

Health and Safety

One of the primary reasons for establishing a strict permitting process for ADUs and JADUs is to ensure safety. These housing units must comply with applicable fire, health, safety, and building codes, be properly connected to utilities to provide clean and safe water, gas, and electricity, and have adequate sewage disposal systems. Without proper permitting, municipalities lack oversight of these units, making it difficult to verify compliance with essential health and safety standards.

Habitability and Fair Housing

Beyond health and safety concerns, municipal oversight of residential rental housing serves to protect both landlords and tenants in various ways, including habitability standards, fair housing compliance, disability access, rent regulations, and other landlord-tenant legal protections. Without proper occupancy permits, landlords and tenants may find themselves without a clear legal framework or appropriate forum to resolve disputes related to renting ADUs and JADUs, potentially leading to uncertainty, unenforceable agreements, and legal risks for both parties.

Housing Needs Assessments and Property Taxes

Municipalities are eager to incorporate unpermitted ADUs and JADUs into their formal housing stock to help meet their Regional Housing Needs Allocation (RHNA). Without an accurate count of existing housing units, local governments struggle to make informed development decisions and may even lose out on financial incentives tied to RHNA compliance. Additionally, legalizing more housing units increases property tax revenue, a critical funding source for local services and infrastructure.

Resource Allocation

With a clearer and more accessible pathway to legalize unpermitted ADUs, municipalities can shift their focus from enforcement to support, prioritizing collaborative efforts that help homeowners achieve compliance rather than relying on punitive measures. This shift allows local resources to be used more effectively, fostering a cooperative approach to expanding safe and legal housing.

Conclusion

While both municipalities and property owners generally prefer permitted ADUs and JADUs, the process of bringing a unit “up to code” can be complex, costly, and time-consuming. Homeowners must navigate multiple fees, including impact fees, connection fees, and capacity charges, while also retaining professionals to address any health and safety deficiencies uncovered during inspections. For many, the financial burden of retroactive compliance is simply too high, leaving a significant number of previously built ADUs and JADUs unpermitted. In fact, a recent study suggests that unpermitted ADUs may outnumber legal ones by as much as three to one (Jo, N., Vallebueno, A., Ouyang, D., & Ho, D. E., Not (Officially) in My Backyard: Characterizing Informal Accessory Dwelling Units and Informing Housing Policy With Remote Sensing, Journal of the American Planning Association (June 3, 2024)).

AB 2533 helps alleviate these challenges by making it easier and more affordable for owners of unpermitted ADUs to retroactively legalize their units. Specifically, the bill:

• Clarifies habitability standards, requiring local agencies to assess unit safety based on specific criteria, rather than broadly enforcing full building code compliance.

• Waives retroactive impact fees, connection charges, and capacity charges, except in limited circumstances.

• Extends the statewide amnesty program (established in 2022 by SB 897) to include ADUs and JADUs built between January 1, 2018, and January 1, 2020—expanding beyond the program’s original coverage of units built before January 1, 2018 that meet health and safety standards.

The SB 897 amnesty program has already proven successful, and this expansion under AB 2533 will provide further benefits for homeowners, renters, and municipalities alike. By easing the path to legalization, AB 2533 helps increase housing supply, improve safety standards, and create a more sustainable and cooperative approach to ADU regulation in California.

Questions?

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